It has been known in the construction of residential and commercial buildings and other structures, such as industrial and manufacturing plants, to provide fire barriers or fire baffles between opposed wall members. These baffles conventionally have been integral wooden or metal panels or screens to prevent fires and flames spreading through the building. Kramer U.S. Pat. No. 3,786,604 discloses a pliable steel trough containing an urea formaldehyde resin foam filling an upwardly opening cavity of the trough. Wire screens, such as shown in Charniga U.S. Pat. No. 4,455,802, and metal fire baffles, such as disclosed in York U.S. Pat. No. 3,334,461, are also known. However, such fire barriers or baffles have not been heretofore effectively used in building constructions known to the inventor wherein the fire barriers or baffles also serve as insulation-melt reservoirs in the event of fire.